The present invention relates to a control instrument including various kinds of switches, for example, a toggle switch, a push button, a display lamp, a connector or a variable resistor. More particularly, the present invention relates to a printed wiring board control instrument which can be mounted on a printed wiring board.
Conventionally, devices of this kind are mounted on a printed wiring board as follows: in a switch , as shown in FIG. 1, terminals 13 projecting from the bottom surface of a switch body 11 are first bent at right angles and a mounting plate 16 with a projection 16a is attached to the switch body 11 so as to form a projection-groove type engagement at 16b. The switch body 11 includes, at its upper portion, a substantially cylindrical sleeve 12. Inside of the switch body is a switching element, operated by a handle 15. Then, the bent terminals 13 of the switch and the projection 16a of the mounted plate 16 are inserted into corresponding apertures of the printed wiring board, 17 respectively, and the switch is rigidly mounted on the printed wiring board 17 by soldering.
However, electronic instruments become very compact due to rapid developments in this field. Therefore, when switches which are, in general, larger than semiconductor devices are mounted on the upper surface of a printed wiring board, they occupy a large amount of space and thus to eliminate any compactness of the instrument. Moreover, where a plurality of printed wiring boards are disposed in parallel and one above another, there has been a problem in reducing projections extending from the surfaces of the printed wiring boards to reduce the size of the gaps between the printed wiring boards.